LB: Lysogeny Broth / Luria-Bertani (Miller) Agar

Add dH₂O to full volume in an appropriately-sized flask. Combine the following, making sure each component fully dissolves before adding the next:

ANTIFOAM: Open the bottle under sterile conditions (near a flame) only, and continue agitating after the addition of the 5% antifoam.

AGAR: Measure 8 grams of agar per 500 ml bottle and add to each individual bottle before aliquoting the LB. Autoclave to homogenize.

Each liter of LB Agar makes 2 bottles of 500 ml.

Notes and variations:

• Common synonyms are Luria-Broth and Luria-Bertani medium.
• This is the "Miller" formulation of LB with 10 g NaCl per liter (1% w/v). Another common formulation has only 5 g NaCl per liter (0.5% w/v)! They are NOT interchangeable.
• If you are performing sacB counter-selection, you may need to use even lower salt concentrations.
• To make "soft" or "top" agar for phage studies, use only 7-8 g agar per liter.